To elaborate on my above post (I remember reading about it but haven't had my reference book at hand at the time of posting). If their camouflage fails, they may rise their wings threateningly or otherwise drop to the ground and feign death if threatened by predators.

I am sure the answer you have given is absolutely correct - the answer I was looking for is:

Stick insects can shed and regenerate their limbs to escape attacks by predators.

Should a bird or other predator grab hold of a stick insect's leg, it can still make an easy escape. The stick insect simply gives up the leg, using a special muscle to break it off at a weak joint. Juvenile stick insects will regenerate the missing limb the next time they molt. In some cases, adult stick insects can even force themselves to molt again to regain a lost leg.

The female begin feeding by chewing off the males head during mating, and the males movements become even more vigorous during this time in its delivery of sperm. In this act the female make sure for reproduction.

What an innovation to increase the chances of successful reproduction: threaten him with death, which speeds up delivery, and then finish him off anyway. Sounds like one of those mad horror movies on women that kill and chop their partners into little pieces. If you think that you've seen it for the first time in a movie, be assured that nature has pre-empted every script and novel writer.